Reports I read said the quake was relatively close to the surface and that the plate involved is very old dense rock which transmits EQ motions very effectively and thus a wide area of locations on the plate were able to feel the event.

By contrast, the plates in the West are relatively new and 'soft' and tend to attenuate any EQ motions and keep them in a narrow area around the point of occurence.

Reports I read said the quake was relatively close to the surface and that the plate involved is very old dense rock which transmits EQ motions very effectively and thus a wide area of locations on the plate were able to feel the event.

By contrast, the plates in the West are relatively new and 'soft' and tend to attenuate any EQ motions and keep them in a narrow area around the point of occurence.

We just had a 4.8 mag earthquake on Friday night near Hollister, CA ( a very active area at the split of the San Andreas Fault and the Calaveras fault). I felt a jolt and then a long (10 second) rolling motion and knew it was on the San Andreas Faultzone East of my area. But after going through the 1989 'Loma Prieta' (6 miles away!) earthquake...you always wonder how much shaking will occur once it starts.....

This post has been edited by idecline: Aug 29 2011, 05:40 AM

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Perception is everything"If you don't know where you are going, any road will take you there". ~ Lewis Carroll

"A good traveler has no fixed plans, and is not intent on arriving" ~ Lao Tzu

Didn't feel the earthquake although many in my state did (North Carolina) but onSept. 2 a tornado cut a swath up the highway right in front of where I work,snapping utility poles (12), uprooting and snapping trees, and creating generalhavoc on both sides of the road. Luckily, no one was hurt although the timeit came through (7 pm) normally sees a lot of traffic on that road.

Didn't feel the earthquake although many in my state did (North Carolina) but onSept. 2 a tornado cut a swath up the highway right in front of where I work,snapping utility poles (12), uprooting and snapping trees, and creating generalhavoc on both sides of the road. Luckily, no one was hurt although the timeit came through (7 pm) normally sees a lot of traffic on that road.

I missed everything! I was at home holding my shivering puppy who jumpson me at the first sight or sound of thunder and lightning. I heard a lot of sirensgo down the highway around that time but there's usually an accident ortwo up there during heavy rains. It wasn't until the next morning as I wasdriving into work that I saw what looked like a surreal accident scene thatmust have involved about 20 cars and all the utility poles on one side of theroad, not to mention much of the fence line and many of the trees. I just never knew how a tornado could jump from one side of the road to another....taking out a line of utility poles on one side and leaving the Security gatehousejust right across the street (with the officer inside!) untouched.

We just had a 4.8 mag earthquake on Friday night near Hollister, CA ( a very active area at the split of the San Andreas Fault and the Calaveras fault). I felt a jolt and then a long (10 second) rolling motion and knew it was on the San Andreas Faultzone East of my area. But after going through the 1989 'Loma Prieta' (6 miles away!) earthquake...you always wonder how much shaking will occur once it starts.....

We had the EQ early in the week and it was followed up by Hurricane Irene for the weekend. What a 1-2 punch for a nothing, nothing week in August.